Washington (CNN) - A man protesting new gun control measures being considered by the Senate was arrested Tuesday on the Capitol grounds when police discovered he was carrying a loaded handgun, CNN has learned.

The arrest happened at 2 p.m. on the Senate side of the plaza in front of the Capitol, according to U.S Capitol Police spokesman Officer Shennell Antrobus.Follow @politicalticker

The man, who was carrying a sign promoting Second Amendment rights, engaged in conversation with police officers who tried to advise him of the rules governing protests at the Capitol. During that conversation, the man told the officers he was carrying a gun. The officers told him that it is against the law in the District of Columbia to carry a gun without a license and he was arrested.

One police source, who declined to be identified, described the man as a North Carolinian who is deeply concerned about protecting gun rights. The source said the man was cooperative when was arrested and not believed to be a threat to anyone.

Antrobus couldn't provide a name of the man nor whether he was still in custody. He said U.S. Capitol Police recommended he be charged with carrying a pistol without a license and carrying an unregistered firearm and ammunition.